Cell Cycle Regulation of the Yeast HO Gene

酵母 HO 基因的细胞周期调控

• 批准号: 6747573
• 负责人: LINDA L. BREEDEN
• 金额: $ 55.73万
• 依托单位: FRED HUTCHINSON CANCER RESEARCH CENTER
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-12-01 至 2006-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6747573
• 关键词: DNA binding protein; DNA damage; DNA replication; Saccharomyces cerevisiae; cell cycle; cell cycle proteins; cell growth regulation; cell proliferation; cyclins; fungal genetics; gene environment interaction; gene expression; gene induction /repression; genetic promoter element; genetic regulatory element; genetic transcription; immunoprecipitation; microarray technology; nucleic acid sequence; nutrition; phosphorylation; posttranslational modifications; protein binding

DESCRIPTION (provided by applicant): The mechanisms that control the cell cycle are remarkably conserved among all eukaryotes. Both mammals and budding yeast commit to another round of cell division during G1. Oncogenic processes exert their greatest impact by interfering with regulators of G1 progression. We propose to investigate the molecular mechanisms which control G1 progression in budding yeast. Our experiments are designed to determine how commitment to the budding yeast cell cycle is regulated in response to nutritional shifts, cell growth and adversities, such as DNA damage. In yeast, as in all higher eukaryotes, cell cycle transitions are governed by cyclin-dependent kinases (Cdks). Nine cyclins have been identified that bind and activate the Cdk of budding yeast (Cdc28). Three cyclins Cln1, Cln2 and Cln3 play critical roles in modulating the G1 to S transition. Our focus is upon determining what controls the expression of these three cyclins during G1. ECB elements activate transcription of CLN3 and other key cell cycle regulators at the M/G1 boundary. Two other promoter elements have been identified that are activated during G1 by Swi4/Swi6 and/or Mbpl/Swi6. These complexes activate transcription of many genes including CLN1 and CLN2, which are rate limiting for the transition to S phase. Our goal is to understand how internal and external signals modulate the activity of these transcription complexes and control the transition to S phase. We have identified one activator and two repressors that influence ECB activity. We will use genetic and biochemical strategies to determine how cell cycle regulation of transcription is conferred by these elements. We will also investigate the regulatory role of Swi6 in activating transcription in G1 and inhibiting transcription in response to DNA damage. We have identified sites at which Rad53 kinase phosphorylates Swi6 in response to DNA damage. We will determine the significance of these phosphorylations to the G1 DNA damage checkpoint. We will also determine whether the consensus site for Rad53 phosphorylation that we draw from our studies enables us to predict the sites at which Rad53 modifies other known targets.

描述（由申请人提供）：控制细胞周期的机制在所有真核生物中非常保守。哺乳动物和芽殖酵母都在G1期进行另一轮细胞分裂。致癌过程通过干扰G1期进展的调节因子发挥其最大的影响。我们建议调查的分子机制，控制G1期进展芽殖酵母。我们的实验旨在确定如何响应营养变化，细胞生长和逆境（如DNA损伤）调节芽殖酵母细胞周期的承诺。在酵母中，与所有高等真核生物一样，细胞周期转换由细胞周期蛋白依赖性激酶（Cdks）控制。已经鉴定了九种细胞周期蛋白，其结合并激活芽殖酵母的Cdk（Cdc 28）。三种细胞周期蛋白Cln 1、Cln 2和Cln 3在调节G1向S转变中起关键作用。我们的重点是确定是什么控制这三个细胞周期蛋白在G1期的表达。ECB元件在M/G1边界激活CLN 3和其他关键细胞周期调节因子的转录。已经鉴定了另外两个启动子元件，其在G1期间被Swi 4/Swi 6和/或Mbpl/Swi 6激活。这些复合物激活许多基因的转录，包括CLN 1和CLN 2，这是向S期过渡的速率限制。我们的目标是了解内部和外部信号如何调节这些转录复合物的活性并控制向S期的过渡。我们已经确定了一个激活剂和两个抑制剂，影响ECB的活动。我们将使用遗传和生物化学策略来确定这些元件是如何调控细胞周期转录的。我们还将研究Swi 6在激活G1期转录和抑制DNA损伤后转录中的调节作用。我们已经确定了Rad 53激酶磷酸化Swi 6以响应DNA损伤的位点。我们将确定这些磷酸化对G1 DNA损伤检查点的意义。我们还将确定我们从研究中得出的Rad 53磷酸化的共识位点是否使我们能够预测Rad 53修饰其他已知靶标的位点。